This invention relates to a disposable diaper having a high ventilation property.
A disposable diaper described in Japanese Utility Model Application Disclosure Gazette (Kokai) No. Sho64-18105 includes a pair of air-permeable and liquid-resistant barrier flaps formed on a pair of transversely opposite side flaps so as to elastically extend in a longitudinal direction of the diaper.
Japanese Patent Publication Gazette (Kokai) No. Hei4-55072 discloses a method for making a backsheet used in a disposable diaper, particularly to obtain such backsheet made of an air-permeable and liquid-impermeable plastic film.
In these Gazettes, the term “air-permeable and liquid-resistant” and the term “air-permeable and liquid-impermeable” are synonymously used. These known techniques may be adopted to improve a ventilation property of the foregoing barrier flaps and portions of a diaper backsheet in the proximity of the barrier flaps intended to surround the wearer's legs and thereby to alleviate undesirable stuffiness during use of the diaper.
The diaper proposed by the above-mentioned techniques will necessarily enlarge a diameter of each aperture formed in the barrier flaps and/or the backsheet in order to improve the air-permeability in these barrier flaps and/or backsheet. However, such measure may cause the desirable liquid-impermeability required for the barrier flaps and/or the backsheet. In other words, the conventional techniques have an antimonic relationship between improvement of the air-permeability and improvement of the liquid-impermeability.